BBC News is stepping up its efforts to reach new audiences on social media platforms after mobile and tablet viewing figures overtook desktop use for the first time in December.

On 16 January, BBC News launched Instafax, a new short-form video news service delivered to Instagram users. The project is a month-long experiment, with three 15-second videos uploaded a day, intended to serve as a roundup of the day's news.

The name is a throwback to the BBC’s former Ceefax service – the world’s first teletext service that ran on UK television until 2012. This is described as the updated version of a text-based, short-form news service for the digital age.

Steve Herrmann, head of BBC News Online, said the trial was a response to changing audience patterns after monthly figures for December, showed mobile and tablet consumption had overtaken desktop for the first time.

The BBC has made subtle changes to its video news services in recent months, including "selfie" pieces to camera filmed on mobile phones being incorporated into mainstream broadcast packages.

"We want the process to be organic, and we're keen to trial new ideas on how we can use our video content to reach new audiences," Herrmann said.

"[BBC News director] James Harding has been clear in his vision to find innovative ways to bring the best of our journalism to new audiences, something our team has been looking at for some time."

There are currently no plans to launch any more social media trials, but BBC News will keep a watchful eye on developments around the world to see how their news can be delivered in new and innovative ways.

Instafax viewers are being encouraged to comment and give feedback. So far it has had mixed reactions ranging from "Instafax is a game changer" to "worst idea ever".

The move is part of the BBC’s ongoing efforts to make its presence felt in digital spaces people are already inhabiting. Last week, unseen footage from a BBC team ambushed in south Sudan made for popular viewing on YouTube.

The BBC is not the first to be testing the value of social media platforms for video news reporting.

NowThis News specialises in short-form visuals for social networks including Facebook, Vine, Twitter and Snapchat. It has created Instagram videos in this format since 2012, the same year the site launched.

NBCUniversal announced it was taking a minority stake in the company last week. NBC News producers will work collaboratively with NowThis to create content aimed at social and mobile platforms.

"We know that news consumption among younger audiences continues to grow, but in order to reach that audience, we need to continue to create video for the platforms they use most," Patricia Fili-Krushel, chairman of the NBCUniversal News Group, said in a statement.

Asked about the BBC's new venture, Ed O'Keefe, editor-in-chief of NowThis News, said: "We're blushing – imitation is the sincerest form of flattery, after all. But when the Financial Times starts mimicking our Snapchats, we'll know we've really made it."